Asbestos yarn



June 12, 1923.

J. A. HEANY ASBESTOS YARN Filed Feb. 5,

. y Patented .lune l2?, 1923.

STATES PATENT ori-ica JOHN .enr/.nn HEANLOF NEW lHAVEN, CONNECTICUT, AssIGNOn, BY MESNE .assum-A mEN'rs, Iro noCxBEsTos PRODUCTS CORPORATION, Af CORPORATION OF DELAWARE ASBESTOS YARN.

Application filed February 5, 1920. Serial No. 856,562.

To all 'whom z't may concern.'

Be it known that I, yJOHN ALLEN HEA'NY',

' a citizen of the United States, and a resident of New Haven, in the county of New Haven and State of Connecticut, have invented a new. and Improved Asbestos Yarn, of which the following is a specification.--

My invention relates to asbestos yarn 'and to the method of producing the same. It

1o has for its general object the production of an asbestos yarn having high tensile strength; having a strong mechanical bond l between its fibers; and capable of effective and lasting use in the most wearing situations.

In my application, Ser. No. 355,117 I have described the manufacture of asbestos yarn by a method which renders it feasible to use little, if any, cotton intermingled with the asbestos fibers and which makes it possible to use the cheaper grades of asbestos commonly known in the art as mill fiber. The method referred to consists in mechanically cleanin the dirty mill fiber and simultaneous y mixing therewith a small ambunt of cotton for the purpose of producing thev required uniformity of mixture and at the same time causin the short asbestos fibers to become entang ed with the cotton fibers and thereby held from escaping with the dust and other impurities; in carding the fiocculent mass thus produced to form slivers of suitable width; rolling the slivers around reinforcing filaments of thread or metal: and finally, twisting the reinforced strands individually to form the finished yarn.

lVhile the yarn made by this method is admirably adapted for many purposes, it is not rugged enough to withstand successfully the violent stresses and abrasions to which it would be subjected when used, for instance, as the constituent of an automobile brake lining.

In order, therefore, to produce an asbestos 4a yarn having high tensile strength and having a very strong mechanical lbond between the fibers, I have conceived and reduced to practice a modification of the method described in the application referred to, which so modification I will now describe by reference to the accompanying drawings in which,

Fig. l is a diagrammatic view` of an apparatus suitable for forming a soft reinstrands centrally forced asbestos strand in accordance with the method described in my above-mentioned application.

Fig. 2 is a'diagrammatic view of a twistmg mechanism adapted to twist two or more strands. formed by the mechanism shown in Fig. 1 1nto a multiple core yarn.

Fig. 3 4is a -diagrammatic developed view Y.

showlng a detail of the `twistin operation.

Fig. Lisa cross section on me 4-4 orv Fig. 3.

Fig. 5 illustrates diagrammatically the operation of one of the steps of the process. v

Fig. 6 is a. diagram showing the twisted isposed of the fibres which are interlocked thereby.

After the asbestos fibers have been cleaned and mixed with a small percentage of cotton and the mixture thoroughly carded, as described 1n my aforesaid application the doffer ring, which is represented in F the numeral 1, delivers the fibers in the form of ribbon-like slivers 2 which are stripped from the doffer by the oscillating comb 4 and deposited upon transfer belt 3. A filament -5 of thread or wire is fed along under the silver and passes together with the latter between the rub motion belts 6, which in a well-known manner roll and condense the sliver around the filament. The strand thus produced is formed by the winding rollers 8 into a roll or cop 9.

The rolls 9 are next taken to a twisting machine in which two or more of the strands are led around feed rollers' 10 and then to a suitable twisting mechanism 11 which twists the strands together and winds `the finished' yarn 13 onto a spool 14.

The multiple core yarn made by this process has a comparatively smooth cylindrical periphery; so far as outward appearances indicate, it seems to be formed by the twisting of a single strand. A large part of the asbestos fibers are tightly clamped between the twisted wires or threads which are lo# cated axially of the yarn and therefore well protected from the disintegrating effects of heat, fluids, etc. These characteristics will be evident from' a consideration ofV what takes place in the different steps of the process.

The action of the rub motion belts 6 in rolling the sliver around the filament 5 efig. 1 by I fects an irregular but more or less spiral ar- 5, in which it will be seen that, as the sliver 1t will enters between the belts, it is first rolled from one of its edges, the fibers being curved spirally around the filament and retaining their spiral arrangement to some extent during the subsequent to-and-fro rolling of the strand as it passes through the belts.

vBecause of the softness of the untwisted strands, they assume a flat form when rolled into cops or rolls.

The flattened strands are fed from tbe rolls 9 insu erposed relation over the feed rollers 10, ig. 2. If the strands happen to be out of alinement, they are drawn into substantially exact superposition by the twisting laction as they passover the upper feed roll l0. This is shown diagrammatically in Fig. 3, which is a developed view designed to indicate the shifting toether of the strands and the spiral foldlng over thereof just prior to the twisting From a consideration of the view roper.

be evident that as the fiat strands shift together in superposed relation they fibers.

are first folded over spirally varound thereinforcing filaments and then twisted together with said filaments, the latter twistlng around each other and tightly clamping between themi many of the asbestos As before stated and as indicated in Fig. 3, the asbestos fibers for the most part are arranged spirally or obliqiiely with relation to the reinforcing filaments, so that when two or more strands are twisted together the filaments ip between them substantially all of the ong bers and a large vpart of the short fibers; then as the twisting proceeds the strands are rst folded spirally around the reinforcing filaments and then twisted abouta common axis which is substantially coincident with the filaments, the latter approaching each other and compressing and clamping between them the asbestos Y' fibers tighter and tighter as their turns per `inch increase.

The resulting yarn has a comparatively smooth exterior appearance, has great tensile strength, and provides a strong mechanical bond between the fibers,

"holding them together with such tenacity Y. that .the yarn can withstand the wearing and tearing effects of the most violent uses.

be composed of"substantially pure asbestos, ifdesired.

Various modifications of vthe above-described process may be madehwithin the scope of my invention. For example, I may twlst a bare metallic filament together with one or more untwisted strands, reinforced.

the twistincv operation and finally occupy av position substantially along the axis of the yarn, the softness of the untwisted strands permitting the filaments to rassume a close juxtaposition in the finished yarn, wherein they securely hold between them many of the asbestos fibers, and wherein all of the asbestos fibers are tightly twisted around the filaments as an axis, thus result-ing in the production of a unitary yarn having the regular and unbroken surface characteristics of a single-strand yarn, but being much superior to a single-strand yarn in tensile strength and in tenacity of bond between the fibers.

I claim:

1. The process of forming asbestos yarn, which consists in twisting together a plurality of untwisted asbestos strands having filamentary reinforcing cores.

2. The process of forming asbestos yarn which consists in applying asbestos fibers in covering relation to each of a plurality of lamentary tensile members, fiattening the filament-reinforced strands thus produced, and superposing and twisting the flattened strands into yarn.

3. The process of producing asbestos yarn, which consists in rolling slivers of carded asbestos fibers around reinforcing filaments in such a way that the fibers are arranged spirally around the filaments, flattening the strands thus produced and superposing and twisting the flattened strands into yarn.

4. The method of making asbestos yarn from the low-grade asbestos commonly known .in commerce as mill fiber, which consists in mechanically cleaning the mill fiber while mixing therewith a smallper- .centage of cotton, carding the mixture of gr VT feeding the 1slivers between longitudinally-progressing and' laterally-reciprocating surfaces to produce soft strands, and 1 finally twisting the strands together with a plurality of reinforcing filaments.

JOHN ALLEN HEANY. i 

